Demon Heart
by MageoftheFairies
Summary: A desperate mother with a sick child makes a contract with a Demon Lord. That baby girl would grow up into a beautiful girl, and that Demon Lord would grow to actually see love and happiness in his life. Their unlikely bond would take them to some very funny and life-changing journeys. Join this goofy pair as they learn important things about themselves and each other.
1. Chapter 1

**I haven't written a new fic in a long time, so I decided to make something funny yet romantic with a touch of drama. This is a story about a Demon Lord and a young girl. Hope you guys enjoy. Oh and long live Gruvia!**

* * *

Her maids were restraining the woman from screaming at the doctor. They were unsuccessful as she was already cursing the old man.

"You're the best of the best. You said you could fix her. You said this and that. Now, you're telling me there is nothing you can do?!" Her screaming turned into crying. The doctor feeling guilty didn't look at the woman.

The maids escorted him out of the mansion. The woman cried hopelessly. Everyone in the estate tried their best to console her, but none of them could understand how she felt.

Her late husband died four months before the birth of their baby girl, his sole heir. Unfortunately, the young baby fell ill few weeks after her birth. The mother begged and demanded for the best doctors around the world. Everyone of them answered the same. She wasn't going to live long.

"Please, I just want to be alone with my child," The saddened servants nodded and closed the door behind them. The woman looked down the crib to see the most beautiful thing in her life.

The baby never cried when she born, and her breathing and heartbeat were very faint. A lot of the times, she would have very dangerous fevers. It was obvious there were a lot of things wrong with her health.

For now, her coughing didn't surface. The young girl's breath was vague. Her fist were the no bigger than walnuts. They were lightly shaking.

She was the exact replica of her mother except her hair screamed her father. She was a creature of beauty. The new mother fell to her knees as her tears hit the floor.

"Please, somebody anybody...save her. Save this innocent child," Silence. "I'll do anything. I lived my life, and I want her to experience that." The silence covered the room. "Please," She softly whispered. There was no hope

Suddenly, the room felt heavy and the air became thin. The scented vanilla candle went out. The lights were cut off. The window bursted open revealing the night sky and the strong wind kicked in.

Frightened, the woman ran to the crib and tried to grab the little baby. She didn't seem to cry or be screamed. As she tried to grab her daughter a spine tingling voice called to her.

"So, you would do anything?" She was terrified, and with all her courage, she turned around to see not something but someone.

There, stood in front of the mirror, was a man of tall stature. She examined him more, the way his dark bangs cover his eyes and how well built he was. He was very handsome. However, when she took a closer look, the wind was knocked out of her. There was something that spread across his back. Something pitch black and cold. They were wings.

"Surprised? Well, since you're a human, this is something new to you," He smirked.

"W-what do you want?" She looked at the non-human creature. "And how did you get here?"

The man smirked again. "Alright, I don't want to make this long. But I have to say that baby there isn't doing so well. Even over here I can tell she won't make it to next month." He pointed at the crib. The woman looked down in sadness. "Yes, I know," There was a pause between them.

"Then, why don't I make a deal with you." She looked at him with her eyes in doubt but with desperation. "I'm listening," With that, he explained the shocking deal.

"I'm going to let that girl live. Simple as that," The woman felt a little hope. She asked him a few questions. "H-how are you going to do that?" There a pause.

"I'll give her my heart of course," He looked at the crib and back at the woman. "But I'm going to need it back eventually. She won't have it forever," His sharp teeth shined in the moonlight as he chuckled.

"What will happen when you take it back?" She was prepared for the worst answer.

"I'll gut her chest open and take it back. Leave her to rot in the soil." And that was the most merciful answer he could give the woman. She was shaking.

"How long will she have your heart?" The man of night put his index finger on his chin thinking. "I'll give her 18 years," The woman was disappointed with the answer.

"18 years?" She begged him to extend the years but that was the farthest he was willing to go.

"Either you let your daughter live for 18 years or she dies during infancy. It's your choice. And let me tell you I'm not waiting for an answer. Take it or leave it,"

She was in a dire situation. She was making a contract with a creature about her child's life. But when she finally took another look at the sick newborn, her decision was final. With all her strength and dignity, she stood up and looked at the handsome monster. "I accept your contract," With that, the man smirked; the room began to turn into ice. He started to chant something.

"O' Seven Ancient Demon Lords! I, Gray Fullbuster, Demon Lord of Ice and Loneliness make a contract with this human. The exchange of my heart for thy life is now coming."

Soon, the baby was floating in air. Markings and symbols began to wrap around her, and finally centered at her upper thigh. "With the sign of the Demon Lords, the Fairy Tail symbol is now tattooed onto to you for eternity! Our contract is sealed!"

The room was going pitch black. And soon enough, the mother fell into a deep slumber. She was woken up by something she never thought she would hear in her life. It was the cry of a healthy baby girl.

She walked to the crib. A beautiful baby was giving a mother reassurance that she was fine. The baby stopped crying and opened her eyes to reveal the color of the ocean. The light of her life was finally burning bright.

The woman kissed and held her tightly. She whispered, "Juvia, I love you very much."

* * *

The maids rejoiced from the miracle, and for four straight years, their lives went well. However, the young mother who had to make the hardest decision of her life fell into an illness that would take her life.

"Juvia, know that Mommy loves you so much. I know you are only 4 years old, but I want to say Mommy isn't going to be around for long. That's why I want you to be a good girl and stay out of trouble. And when you reach your 17th birthday, unlock the safe hidden in my room. You will only find a letter from me, and it will tell you something important alright? Stay strong dear. My last wish for you sweetie is that you live your life to the fullest!" With that said, Juvia and her mother spent their last day together.

"Juvia promises to live her life. For her and for Mommy!" She swore to all of the servants. Servants didn't describe what they were to the little girl, rather, they were her family. "Juvia will do what Mommy wishes! This is what Juvia wants too,"

* * *

He watched as the little girl made the speech to her family. He gave that infamous smirk of his. "Seems like she doesn't know about _that_ thing. If she wants to live her life, then maybe I should help make it _fun_,"

With that, he went back to the Underworld.


	2. Chapter 2

After the death of her mother, Juvia Lockser always set off for adventure when she was little. Since she was still a child, the maids wouldn't allow her outside of the estate for her 'adventuring'.

As she got older, one thing kept her from filling her mother's wishes. It was the rain, full of gloom and sadness. She came to see the rain as one of her main enemies. She hated it because terrible things seem to happen to her when it came pouring.

_Its raining more than usual._ She thought as she sliding through the hallways. _They won't even let Juvia go outside. _She began to grow tired and sat on a window sill. It was a bit depressing when she looked out. Everything was dark and wet.

"Juvia rarely sees the sun anymore," she muttered to herself as she brought her knees to her chest. "Juvia wishes a miracle could happen," She looked back outside. Even if miracles were myths, it still would've been nice one happened. She was about to retaliate to her room until she noticed something off about the weather.

Suddenly, she noticed the wind became more heavy and the temperature was getting colder. Her breath was visible through the glass. "Huh? What's going on?" Then, the most weirdest and a little disturbing thing happened.

The clouds turned black and began to swirl around. It finally made a shape of a portal. _How come no one is noticing this?!_ She was about to warn the servants until she saw something unusual. From the portal thingy, someone fell out of it.

Watching the person fall helplessly, Juvia could only watch in horror and amazement. What really struck her odd was that person who fell from the sky, landed in _her _garden.

She stood there for a second trying to take this all in. Finally, all she could say was, "There is a person, who fell from a cloud thingy, in Juvia's garden... Eh, she has seen worst," She wanted to know who this mysterious person was before the guards could find them, and she didn't want the maids to find out she was outside in the rain.

Juvia did the most smartest and safest way of sneaking out of the house. And that was to jump out of the window from the 4th floor.

* * *

He sat there on his throne kicking the little pebbles in front of him. "So fucking bored," He started to hum to himself until the door slammed open. There, stood his friend and another Demon Lord, Natsu Dragneel. "Piss off flame brain," He shooed his friend away.

"Gray, stop being a dick, I only came here to invite you somewhere," With his blood-shot wings, he flew to his frustrated friend. "You wanna prank Laxus?" The raven haired man looked at him like he was asking for a death wish.

"No, I wanna do something I've never done before," he pressed his cheek against his palm.

"Well, since you don't have your heart right now, you aren't able to go to full power. That sucks," Natsu knocked his forehead. "How many years has passed since you gave your heart to that baby, and I recall that you said you were going to make her life _interesting_ when she was a little chubby ball. What happened to that?" He looked up into the ceiling floating around. Waiting for his answer.

"I thought it would be fun, but all she did was think she was a unicorn or pirate inside the house, so I got bored and left. I mean, I had better things to do. And I haven't kept count of how many years passed. Time will fly by as always," He sulked from boredom. It even made his pink-haired friend want to help him out for once.

There was an awkward pause.

A lightbulb flickered on above Natsu's head. "Hey stripper, can you sense where your heart is?" A simple nod was his answer. "Transfer the feeling to me,"

He raised an eyebrow at his friend's directions. "What the hell are you gonna do-" Natsu cut him off by saying it would help him.

"Got it!" All of a sudden a flame-engulfed portal was standing right in front of them. "Might want to hide your wings," He gave him an evil grin. It was clear what he was going to do. It was typical Natsu Dragneel with his crazy and insane ideas.

"Natsu what the fuck are you-" Before he could finish his fellow Demon Lord punched him into the portal. Before it closed, he saw his friend giving him a smile and a thumbs up. "I just helped with your boredom problem. Have fun!"

"Fuck you!" That was the last thing he said before falling to the ground in the human world.


End file.
